This retrospective study will ascertain cumulative observed and cumulative relative survival rates for diabetics according to severity of retinopathy in the worse eye. The clinical material is a series of visits by 595 patients to the University of Wisconsin Diabetic Eye Clinic where first visits occurred between January 1961 and December 1968. The patients were followed through December 1975. Advantageous characteristics of these data are the long and complete follow-up (only two patients in the series were lost to follow-up).